Sheet stripping members for fixing device for fixing images of an original document on sheets of copy materials

Abstract

A couple of copy sheet stripping members are provided for scraping away a copy sheet adhered strictly to one of two rollers which are driven to fix images of an original document on the copy sheet in pressure engagement. At least one of the copy sheet stripping members is secured removably from the roller while the copy sheet is not transferred out of the rollers. The copy sheet stripping member becomes pressed against the roller in accordance with the transferring of the copy sheet which is detected by a sensing means. The copy sheet stripping member is free of residue attached on the roller because the period of time where the engagement between the roller and the copy sheet stripping member is kept is very short. The other copy sheet stripping member can be further disposed to assure both the scrape of the copy sheet and the removal of the residue on the roller, the copy sheet stripping member being continuously pressed against the roller.

What is claimed is: 
     
       1. In a copy sheet stripping device within a copier, said copier including a pair of rollers for fixing images of an original document on a copy material by pressure engagement between said rollers, the improvement comprising: means for moving the copy sheet stripping device into engagement with one of said pair of rollers to scrape away the copy material from that roller in synchronization with the approach of the copy material toward the rollers, and for moving the copy sheet stripping device away from that roller in synchronization with the separation of the copy material from the rollers.   
     
     
       2. The copy sheet stripping device according to claim 1 further comprising: stripping means for continuously cleaning one of said rollers so as to scrape away the copy material adhered to that roller and pick off residue adhered to that roller.   
     
     
       3. A copy sheet stripping device within an instrument for fixing images of an original document on a copy material by using a pair of rollers in pressure engagement, comprising: first means for detecting the approach of the copy material toward said pair of rollers and providing a first detection signal in response to the approach;   second means for sensing the exit of the copy material from said pair of rollers and providing a second detection signal in response thereto;   copy sheet stripping means for stripping the copy material from one of said pair of rollers; and   energization means which is activated by the first detection signal to move the copy sheet stripping member into engagement with that roller and, subsequently activated by the second detection signal to move the copy sheet stripping member away from that roller.   
     
     
       4. The copy sheet stripping device according to claim 3, wherein the energization means comprises a spring means which is continuously energized so as to force the copy sheet stripping member into disengagement with said one of said pair of rollers and a solenoid means which is energized to position the copy sheet stripping member in engagement with that roller and disenergized to move the copy sheet stripping member away from that roller. 
     
     
       5. The copy sheet stripping device according to claim 3, wherein each of said first and second means comprises a microswitch. 
     
     
       6. The copy sheet stripping device according to claim 3, wherein each of said first and second means comprises a photo detection system. 
     
     
       7. A device for separating sheets from a moving member having a width transverse to the direction of travel, comprising: stripping means for separating said sheet from said moving member, said stripping means being rigid and having an edge capable of engaging the moving member;   means for sensing when said sheet is in close proximity to said stripping means; and   means responsive to said sensing means for moving said stripping means into engagement with said moving member only when said sheet is detected by said sensing means.   
     
     
       8. The device of claim 7 wherein said moving means comprises: solenoid means for moving said stripping means into engagement with said moving member in response to the detection of said sheet by said sensing means; and   resilient means for maintaining a bias force on said stripping means for retaining said stripping means into disengagement from said moving member when said solenoid means is not activated.   
     
     
       9. The device of claim 8 wherein said means for sensing comprises at least one microswitch. 
     
     
       10. The device of claim 9 wherein said means for sensing comprises at least one photodetector. 
     
     
       11. The device of any of claims 7-10 wherein said moving member is one of a pair of rollers for fixing images of an original document on the sheet in a copier. 
     
     
       12. The device of claim 11 further comprising: fixed stripping means for maintaining said one of a pair of rollers clean by continuously removing any residue from that roller.